Alcantara is not one of the team's Core Four prospects (a designation that probably needs to be changed to the Big Six given the trade for Addison Russell and 2014 first-round Draft pick Kyle Schwarber's instant impact), but the dynamic little everywhere man from the Dominican Republic beat Javier Baez, Kris Bryant, Jorge Soler and Albert Almora to the Major Leagues.

He was playing in his third game on Friday, his first in front of the ivy-colored walls and iconic scoreboard, and wouldn't we all like to know how Sammy Sosa's old home looked through his wide eyes?

Alcantara was a difference-maker in the 5-4 victory over the Braves, but even before the ninth-inning dramatics it was clear that it was a rush for the 39,544 fans -- the biggest crowd of the season, including Opening Day -- to see a newcomer who could play a role on future playoff teams.

"I thought the fans, you could sense they were happy to have us home," said manager Rick Renteria, whose team went 5-6 on a trip to Boston, Washington and Cincinnati. "I'm hoping I read it right. We've been on the road a lot this year. You could feel the energy, obviously. Even though we got tied, they stayed with us. Obviously, I thought they were very excited for us to pull it out in the end. You could hear the buzz."

Alcantara, promoted on Wednesday in Cincinnati when Darwin Barney left for paternity leave, is a human pinball machine when it comes to registering stats. He does everything you can do on a diamond -- good and bad -- and the numbers often pile up in a hurry. That was the case Thursday, when he was 4-for-5 with a double, a triple and a sacrifice fly.

Protocol dictated that players rush the field to mob Ruggiano, but the pile could have just as easily been on the 22-year-old Alcantara, a holdover from the Jim Hendry regime who was hitting .307 with double figures in doubles (25), triples (11), home runs (10) and stolen bases (21) in 89 games for Triple-A Iowa when he was promoted.

Renteria admitted that Alcantara's arrival has energized the Cubs' clubhouse.

"When you have a young person come in fresh to the big leagues, there's a lot of energy, there's a lot of excitement," Renteria said. "There's a willingness to go out and show what you have. This young man has the energy and the desire to be out there. He's very composed. Good for him."

Arrieta, acquired last year from the Orioles in a trade for Scott Feldman, continues to look like one of the best additions for Epstein and Jed Hoyer in Chicago. His emergence this season made it a little easier to trade Samardzija and Jason Hammel to the Athletics, and he pitched as well against Atlanta as he did against the Nationals in his first start after the Samardzija trade.

Relying on his tight slider more than ever, Arrieta has found the command that escaped him in Baltimore. He worked 7 2/3 innings on 98 pitches against the Braves, allowing four hits and three runs. Bethancourt's hit off Hector Rondon kept Arrieta from running his record to 6-1, but he didn't seem to mind. He'll take the 1.95 ERA and 1.01 WHIP -- and maybe in a year or so the long-term contract extension that Samardzija declined.

Arrieta admits that he expects himself to fill the void left by the Samardzija/Hammel trade.

"Yeah, I kind of slowly put myself in that role, even when those two guys were here, to be one of those guys," Arrieta said. "I've commented on it a little bit in the past, but it's a role I've been in before. I'm pretty comfortable with the responsibilities that come along with a role like that. It's something I embrace and look forward to continuing to be in this role, to help guys establish themselves, combat the struggles that take place at this level."

As usual, the Cubs received impactful hits on Friday from Castro and Rizzo, the 24-year-old All-Stars who are bouncing back from down years in 2013. They are veterans before their years, having combined to play 1,083 Major League games, too many of them with their team in last place.

No one knows when Epstein will decide to take the wrapping paper off the talent that awaits in places like Iowa, Tennessee and Florida. But Alcantara reinforces what scouts have been saying. These guys are worth the wait.

"Guys like Alcantara, we know we have some guys in the pipeline who can definitely help us in the future," Arrieta said. "We look forward to seeing these guys -- Baez, Bryant and a couple of other young guys. It's going to be a fun period of time in the next six, eight months, toward the end of this season, the beginning of next season, to see those guys blossom and continue to grow, get some experience up here. We want to win here, regardless of the situation on the roster. Our clubhouse feels like we can win games. With that mentality, on top of that, getting some good players to fit in here, that definitely helps."

For the first time in a long time, seeing was believing.

Phil Rogers is a columnist for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.